A male longfin mako shark Isurus paucus of 303 cm total length was found during the monitoring of small scale fishery in Nuevo Torno Largo, Tabasco. This is the first record of the species in the south-eastern Gulf of Mexico. The specimen was caught by a small longline vessel at 18o49′45″N 94o08′14″W. Snout and ventral coloration, pectoral fin length and dorsal fin position were used to verify the identification.